NAME

       MPI_Ibarrier  -   Notifies  the  process  that  it  has  reached  the  barrier and returns
       immediately

SYNOPSIS

       int MPI_Ibarrier(MPI_Comm comm, MPI_Request *request)

INPUT PARAMETERS

       comm   - communicator (handle)

OUTPUT PARAMETERS

       request
              - communication request (handle)

NOTES

       MPI_Ibarrier is a nonblocking version of MPI_barrier. By calling MPI_Ibarrier,  a  process
       notifies  that  it  has  reached the barrier. The call returns immediately, independent of
       whether other processes  have  called  MPI_Ibarrier.   The  usual  barrier  semantics  are
       enforced  at  the  corresponding  completion operation (test or wait), which in the intra-
       communicator case will complete only after all other processes in  the  communicator  have
       called MPI_Ibarrier. In the intercommunicator case, it will complete when all processes in
       the remote group have called MPI_Ibarrier.

THREAD AND INTERRUPT SAFETY

       This routine is thread-safe.  This means that this routine may be safely used by  multiple
       threads  without the need for any user-provided thread locks.  However, the routine is not
       interrupt safe.  Typically, this is due to the use of memory allocation routines  such  as
       malloc or other non-MPICH runtime routines that are themselves not interrupt-safe.

NOTES FOR FORTRAN

       All  MPI  routines  in  Fortran  (except  for MPI_WTIME and MPI_WTICK ) have an additional
       argument ierr at the end of the argument list.  ierr  is  an  integer  and  has  the  same
       meaning  as  the  return  value  of  the  routine  in  C.   In  Fortran,  MPI routines are
       subroutines, and are invoked with the call statement.

       All MPI objects (e.g., MPI_Datatype , MPI_Comm ) are of type INTEGER in Fortran.

ERRORS

       All MPI routines (except MPI_Wtime and MPI_Wtick ) return an error value;  C  routines  as
       the  value of the function and Fortran routines in the last argument.  Before the value is
       returned, the current MPI error handler is called.  By default, this error handler  aborts
       the  MPI  job.   The  error  handler  may  be  changed  with  MPI_Comm_set_errhandler (for
       communicators), MPI_File_set_errhandler (for files), and MPI_Win_set_errhandler  (for  RMA
       windows).   The  MPI-1  routine  MPI_Errhandler_set may be used but its use is deprecated.
       The predefined error handler MPI_ERRORS_RETURN may be used to cause  error  values  to  be
       returned.   Note  that  MPI  does  not  guarantee that an MPI program can continue past an
       error; however, MPI implementations will attempt to continue whenever possible.

       MPI_SUCCESS
              - No error; MPI routine completed successfully.

       MPI_ERR_ARG
              - Invalid argument.  Some argument is invalid and is not identified by  a  specific
              error class (e.g., MPI_ERR_RANK ).
       MPI_ERR_COMM
              -  Invalid  communicator.   A  common error is to use a null communicator in a call
              (not even allowed in MPI_Comm_rank ).
       MPI_ERR_OTHER
              - Other error; use MPI_Error_string to get more information about this error code.

                                            2/22/2022                             MPI_Ibarrier(3)